Thanks for clearing that up.
I remember hearing that development of docker-engine was ceasing, but could obviously live on as it was forked. I guess rootless is some of the work that Docker (company) wanted to keep proprietary and out of this open-source project.
Really quite a shame, although understandable from a commercial perspective.
Assuming that these improvements are finding their way back into an open-source project, I'm glad to hear about this work from minikube and Podman.